Immersion heater



Jan. 14, 1969 F. GETHING 3,421,496

IMMERSION HEATER Filed May 22, 1967 Sheet In of 2 Fran/0 565551129, 59 2% 7 Jan. 14, 1969 F. GETHING IMMERSION HEATER Sheet Filed May 22, 1967 United States Patent Claim ABSTRACT OF THE DISCLOSURE An immersion heater having a housing is adapted to be seated on the edge of a tank containing liquid to be heated. The housing carries a chamber adapted to furnish fuel and air to a plurality of nozzles disposed in said chamber. An equal plurality of heat exchange tubes extend downwardly from the chamber and said plurality of nozzles to be immersed in the liquid in the container with the tubes being of diminishing size and there being provided a drain for collecting condensing products of combustion with the drain being in communication with that portion of the immersed tubes wherein the products of combustion are still primarily in gaseous form.

The invention relates to an immersion heater and more particularly to a gas fired immersion heater having a plurality of heat exchange tubes to be immersed in a liquid to be heated.

It is a general object of the present invention to produce a new and improved immersion heater of the character described.

It is a further object of the present invention to provide an immersion heater arranged to be seated on the upper edge of an open container containing liquid and provided with a plurality of heat exchange tubes immersible in the liquid with the tubes being equipped with means for collecting and disposing of condensing products of combustion so as to prevent flooding of the tubes as well as preventing corrosion thereof.

While it will be readily apparent to those skilled in the art that the immersion heater of the present invention is adaptable to many uses, it is particularly useful in providing a large source of heated water for car washes. In connection with car washes there is normally provided a concrete tank usually open so as to be at atmospheric pressure which tank prov-ides the source of water to be used in the car washing operations. The water must be heated in order more satisfactorily to perform its function and the immersion heater of the present invention is particularly adapted for use in connection with such open tanks inasmuch as it is arranged to be seated on the upper edge of the tank with the heat exchange tubes used in connection therewith immersed in the water in the tank.

Thus, it is a further object of the present invention to provide an immersion heater particularly adapted to be seated on an upper edge of an open container for water which heater is provided with a plurality of tubes immersible in the water together with gas fired means for produsing a flow of hot gases through the tubes.

Other and further objects and advantages of the present invention will be readily apparent from the following description and drawings in which:

FIG. 1 is a side elevational view partly broken away of an immersion heater embodying the features of the present invention;

FIG. 2 is a view like FIG. 1 taken from a position 90 therefrom; and

FIG. 3 is an enlarged detail view taken along line 3-3 of FIG. 2.

While an illustrative embodiment of the present invention is shown and will be described in detail, it should Patented Jan. 14, 1969 be understood that the embodiment illustrated is intended to set forth the principles of the invention and not to limit the scope thereof. The scope of the invention will be pointed out in the appended claim.

Referring now to FIGS. 1 and 2 of the drawings, there is shown an immersion heater 10 provided with a housing 11. The housing is provided with portions 12 and 13 adapted to seat upon the upper edge of a container (not shown) for liquid to be heated. As illustrated, the housing is arranged to be positioned above the upper level 14 of liquid in the container and is provided with a control panel 15 housing controls operative to response to temperature of the liquid to be heated to supply additional heat thereto or to cut ofi the source of heat when not needed. A plurality of gas nozzles 16 are located in a chamber 17 in the housing with the gas exited from the nozzles arranged to be ignited by a ribbon type pilot burner 18. The pilot burner is of the constant type, i.e. is ignited before the gas burners are supplied With gas and which continues to burn during the time the gas exiting from the nozzles 16 is burning. The control 15 senses the ignition of the pilot light and operates to cut ofi the flow of gas to the nozzles in the event the pilot light is extinguished. Pre-ignition of the pilot is achieved in the usual fashion by means of the electrode 19. Gas is supplied from a gas source 20 to a gas conduit 21 connected to each of the gas nozzles with the source being controlled, of course, by the control 15 as previously described. Air for combustion is supplied by a centrifugal blower 22 having a discharge conduit 23 connected to a distribution conduit 24 opening into the chamber 17. The flow of air through the conduit 24 is regulated by a damper 25 under the control of the control device.

A plurality of fire tubes 30 open at one end into the chamber 17 and the flame from the gas nozzle 16 is directed downwardly into said open end. The tubes have a first vertical portion, as shown, which connects by means of an elbow 31 into a horizontal portion 32, constituting the lowest portion of the heat exchange fire tubes. The portion 32 is connected by means of elbows 33, 35 and 37 to a plurality of horizontal tubes 34, 36 and 38 which provide tortuous passages for the hot gases produced in the first vertical portion of the fire tubes. The horizontal portion 38 of the fire tubes terminates in an upwardly extending portion 39 which communicates with the atmosphere. As the major portion of the tubes just described is beneath the surface of the liquid, the heat of the gases is transferred to the liquid and thus heats the same.

As indicated in the drawings, the portions 30 and 32 of the tubes are of larger transverse diameter than the portions 34, 36 and 38. This provides a more uniform flow of gases through the tubes. As the gases transfer heat to the water heating the same, the volume of the gases decreases.

As previously noted, the portion 32 of the fire tube is the lowest portion of the heat exchange assembly and each of the portions 32 of the tubes shown is connected to a common drain 40 which is connected in turn through a coupling 41 to a vertically extending pipe 42 opening to or connected with the atmosphere. Inasmuch as the condensed products of combustion have a tendency to move to the lowest portion, the location of the drain 40 in the position shown enables it to operate as a collector for such condensed products, primarily water. Furthermore, the fact that the drain 40 is located quite close to the source of heat, i.e., that initial portion of the fire tubes wherein the gases passing therethrough are still quite hot, the condensed products of combustion collecting in the drain 40 are vaporized by the heat and pass out to atmosphere through the pipe 42.

With the products of combustion disposed of in the manner described, the heat exchange tubes will not become 3 blocked through the accumulation of condensed water therein nor will the corrosion which would otherwise 0ccure be encountered in immersion heaters of the present design.

By reason of the foregoing, the particular design shown in the drawings will be particularly useful in the environment suggested, namely, a readily installable immersion type heater particularly useful in heating water in open tanks.

I claim:

1. An immersion heater of the character described comprising: a housing adapted to be supported above a container for liquid to be heated; a chamber carried by the housing; a plurality of fire tubes each opening at one end to the interior of the chamber and each having a first portion extending downwardly from the chamber for immersion in said liquid, a second portion providing tortuous passages for hot gases, and a third portion extending upwardly from the second portion and communicating with the atmosphere; a plurality of gas nozzles in the chamber each directed into the open end of a different one of said fire tubes; means including a blower and a distribution conduit for supplying combustion air to said chamber to provide uniform air distribution to each gas nozzle; a drain connected to a lower part of said first portion for collecting condensed products of combustion; and means connecting the drain to the atmosphere.

References Cited UNITED STATES PATENTS 867,457 10/ 1907 Whitfield.

940,445 11/1909 Elder 12691 1,166,411 12/1915 Davis 126360 2,543,835 3/1951 Dewey 126360 2,617,407 11/1952 Johnson 126360 2,696,815 12/1954 Johnson 126360 2,698,616 1/1955 Kudobe 126-360 3,124,122 3/1964 Baron 126360 FOREIGN PATENTS 817,591 7/ 1949 Germany.

FREDERICK L. MATTESON, JR., Primary Examiner. R. A. DUA, Assistant Examiner. 

